


Birds of a Feather

by LookingForOctober



Category: Mirabile - Janet Kagan
Genre: Gen
Language: English
Status: Completed
Published: 2017-12-23
Updated: 2017-12-23
Packaged: 2019-02-18 17:15:22
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,061
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13104813
Author URL: https://archiveofourown.org/users/LookingForOctober/pseuds/LookingForOctober
Summary: Over a decade post-book, a problem with hummingbirds threatens an important ecosystem on Mirabile.





	Birds of a Feather

**Author's Note:**

  * For [nenya_kanadka](https://archiveofourown.org/users/nenya_kanadka/gifts).



Summer's always a busy season on Mirabile, and that summer in particular I'd spent months tracking the elusive jabberwombat through the forests of the south. I was ready for a break when I got this note: 

Ilanith--  
Remember those hummingbirds? The ones that we finally got established on Cure Island to pollinate the trees there?  
They're dying again.  
Come as soon as you can, we need your expertise.

P.S. Bring your own tent, and make sure there's room in it for Leanne.

When Annie Jason Masmajean says "come", then you jump on it right away. It's a habit almost as old as I am, and it wasn't about to change now just because I was a fully qualified jason myself, not a kid watching Mama Jason with stars in my eyes.

So I cleaned off my best two person tent and booked a flight to Cure Island aboard Mirabile's only passenger plane.

It used to be that a hover could take you anywhere humans had settled on Mirabile, but a lot of new territory had opened in the last few years, and people had rushed to settle in the most distant areas -- partly out of fear of the Mirabilan Slowstep.

Despite the name, it's not a dance; it's a disease that slows down the body. We didn't know a lot about it, except that it was similar to a disease that affected stickytoes, and eight years ago it had crossed into the goat population and then on to humans.

"I hoped this would never happen," Mama Jason said. The rest of the population blamed the jasons half the time, and begged us to stop it the whole time. True to its name, the slowstep spread slowly.

We stopped it before the first fatality, and the cure -- an extract from the fruit of an obscure tree from Earth -- reversed the damage.

"We were lucky," Mama Jason said, and put everything she had into establishing a population of the trees on an island. We modified the EC of that island ruthlessly to support those finicky trees.

That was Cure Island.

Olga Pilot Winstead, who flew the plane, helped me stow my baggage in the plane. "You're in just ahead of the rush," she said.

I didn't figure out what she meant until I got there. Noisy, aka Leo, aka Mama Jason's husband, aka Papa Jason, directed me away from the main campsite, down to a little clearing near the shoreline.

"We're hosting a conference to decide what to do about the pollination problem," he explained. "The main campsite's going to be full up."

"So that's why Mama Jason wanted Leanne to stay with me!" Leanne was Mama and Papa Jason's kid, and she was being raised by Elly, the best raiser on Mirabile.

"I think she had something more in mind, but I'll let her tell you," Noisy said evasively.

I shrugged and set up the tent. If they wanted to have mysteries, I'd just do my job. That would show them.

 

I spent the next couple of days exploring the island, with Leanne as my guide. Her family were all jasons, so it didn't surprise me that she knew all the basics, just like me at her age.

We hiked all the way around the island, along the rocky shoreline and then up to the top of the big hill in the middle, passing through meadows filled with twice as many rocks as sheep. The sheep weren't for wool; they were to keep any competing tree species off the island by eating any young saplings. The only trees we saw were a giant Mirabilan species that had been left in place when the island's EC was modified; they were tall and thick, with long fronds standing straight up at the top; we rested in their shade when we got tired.

The orchards were fenced off, on the side of the hill that was out of the wind. Leanne skipped ahead as we approached, and keyed the code into the gate. "There's an alarm too," she said, wide-eyed.

On Mirabile, we tend toward trust, because we're all in it together, but cure island was different, apparently. Or maybe someone had just gotten paranoid when things started going wrong.

We locked the gate behind us and wandered through the trees. They were still thin, even though they'd been force grown and then grafted onto strong root stock from an earlier attempt at an apple orchard. Sunlight filtered in amongst the thick green leaves -- the trees were healthy -- but the fruit was sparse.

We took samples from several of the trees, to go along with the samples we had taken everywhere else on the island, but we didn't linger long.

"When Mama brought me here a few years ago, the whole air was full of hummingbirds," Leanne said. "But that was in the spring."

I nodded. "It's like trying to solve the mystery after someone has come and erased all the clues that might have been here in the spring," I said.

"Don't worry, you're a great detective," Leanne said. "That's what Jen told me."

I smiled. Jen and I had been raised together, and she was now a jason like me, but her specialty was dealing with large animals. "Did she tell you to be careful of hippopotamuses?" I asked. We'd gotten our first elephant on Mirabile a few years ago, kept it because the openers begged us -- but the hippopotamuses in the secondary helix of that elephant were never going to see the light of day if any jason could help it. Just too damn dangerous.

Leanne nodded solemnly. Jen brought up her specialty whenever she had a chance, so Leanne had probably heard quite a lot about them, or maybe she had enough imagination to read between the lines of the information in the database.

"We need to process all these samples before we can put on our detective hats," I said. "Are you with me?"

"There's one more thing," Leanne said.

She led me to a glass enclosure on the edge of the orchard, just inside the fence. The doorway was open, and inside the air was damp and hot and the vegetation was thick. Flowers bloomed riotously in every bit of sunlight entering through the glass.

Hummingbirds perched listlessly on several branches, but I didn't see them until Leanne pointed them out. From the information I'd seen, I'd expected bright jeweled feathers, but these birds were dull, and their feathers seemed ragged rather than sleek.

"They don't fly much," Leanne explained. "They wouldn't even fly away when Mama opened the cage."

"These are the birds that wintered in the greenhouse?" I asked. 

"Mostly the ones that hatched last year," Leanne said.

We carefully took samples. Then we took all our samples back to our tent and started running them through the computers. For a full EC analysis, we had samples of just about everything that grew or lived on the island in any profusion. 

There were a few surprises, mostly plants that must have grown from seeds carried to the island by the wind, but on the whole, the island ecosystem was very well understood already, and hadn't changed much since it had been established. 

Which was very strange to me.

Generally, on Mirabile, random chance and the extra helices in the DNA of every species imported from Earth interacted with the environmental conditions to give us just about anything that might possibly be viable on Mirabile -- which was the point. The extra helices were a gift and a curse -- meant to supply us with species that the gene bank might be missing, or that might have been damaged in transit. But sometimes we ended up with dangerous dragon's teeth, cobbled together by chance and a genetic process we didn't always understand.

It was originally intended as a backup system, but it had become a way of life on Mirabile, unpredictable but necessary. It was the extra helices that allowed our earth species to adapt to the environmental conditions with extra speed. 

But on Cure Island, unpredictable was not acceptable, so the ecosystem that I studied on my computer screen at night was less complicated than what I was used to. Which just made it more puzzling that it could harbor secrets.

"Something's not working out as planned," I told Leanne, who was sitting cross-legged on her cot with her own computer on her lap, running supplementary simulations. 

All the simulations predicted health and happiness for the hummingbirds in this EC. All the simulations must be missing some important piece of information about the EC, that much was clear.

"What else can we check?" I asked Leanne. 

We made lists, and then the next day we headed out again, and gathered samples and ran gene scans on them, trying to find something that didn't match the simulations. Some poison that the hummingbirds might be affected by; some nutrient they might be missing; some parasite or disease.

We collected much more data than a standard EC survey, but all we did was eliminate hypotheses.

There was no sign that anything in the EC was harming the hummingbirds, and all the plants that the hummingbirds depended on for food were present and accounted for.

"But something must have changed, or not worked out like the simulations predict," I said.

Leanne sighed dramatically. "We'll just have to collect more data, and keep looking for discrepancies," she said. "Unless you have some secret detective method that no one else knows about?"

"No secrets any more," I said. The methods that had been used to stabilize cure island had once been a secret between me and my siblings, but that was a long time ago.

"Are you _sure_ you don't have any secret methods that could make everything easy? Mama said you might. She said you were very secretive when you were my age, but she trusted me to wrinkle out any secrets you might have."

"I wouldn't keep any secrets from you," I said. "You're my apprentice, right?"

Leanne lit up. "Well, I thought I was," she confided. "But since Mama's been too busy to ask you officially..."

"Oh," I said, laughing. That must be what Noisy had meant. I grinned at Leanne. "Who needs official. We get on, we'll work together."

"Okay," Leanne agreed comfortably. "I'll be the best apprentice you ever had."

 

The members of the conference continued to spend all their time arguing. Mama Jason stopped by some evenings, with an air of contained anger that I knew wasn't directed at either Leanne or me. Just all that desire to knock some heads together spilling out after a long day, and no knockable heads. 

I was sorry that I didn't have any good news about my own efforts to solve the problem.

After listening to our progress, Mama Jason shook her head. "They want to give up on hummingbirds and pollinate the trees by hand," she growled.

"Uh oh," I replied.

"I gave them some time estimates, and asked them if they wanted to establish a new occupation designation. I told them I didn't think 'Pollinator' was going to be very popular."

"I wouldn't do it," I agreed. 

"Then they suggested modifying the plants so that they pollinate themselves by wind."

"So are you pulling Susan in to tell them how difficult that is?"

"I hope I don't have to," she said, but I'd obviously put an idea in her mind, because Susan showed up a few days later.

"What are you doing here?" I asked. "I thought I was the specialist of last resort."

"For now, I'm staying here while investigating a problem on the mainland. I caught a ride with some of the conference attendees."

"You're backup, in case Mama Jason need it," I said. 

"So are you," Susan said.

I groaned. 

"Didn't you realize?"

I shook my head, then rallied on the thought that Mama Jason could yet prevail. "Do you need help setting up your tent?" I asked.

As we pounded stakes into the ground, Susan told me more about the problem on the mainland. "They've had trees falling over --" She pointed to one of the native trees, the tall sort with the upright fronds. Or partially upright fronds right now, as it neared sunset; the fronds collapsed against the side of the tree when the sun wasn't shining on them, maybe to preserve water. 

"That kind of tree, but something happens and they loose their structural integrity," Susan said.

When I went over to check out the tree -- it seemed well constructed, but pests can get into anything -- I found Leanne lurking in the shadows like an uncertain moth, attracted to the sound of conversation.

"Come meet Susan," I said cheerfully. "We were raised together. You'll like her."

She looked away, unusually shy.

"Hey," I said, but Susan was right behind me.

"Leanne! Want to come to the mainland with me? We'll be taking canoes, and I know how much you like canoes."

I didn't know that Leanne liked canoes. I growled, like a bear, or like a Masmajean. "Don't be taking my apprentice away from me."

I thought Leanne would take it as a joke, but she looked guilty.

Susan, on the other hand, laughed. "You're welcome to come too," she offered. "Take a break, let your mind wander for a day. If you've already been here a week, you probably need it."

"I'm tempted," I said.

And Leanne, realizing that "apprentice" didn't have to be an exclusive arrangement, looked up and grinned at me. "I'm tempted too," she said.

"Go," I said, waving my hand at her energetically. "You need a break too."

In the morning, I saw Susan and Leanne off, and then retreated to my tent for some concentrated simulation-building and data analysis. To no avail. The breakthrough I was looking for evaded me all day.

I only emerged from my tent when I smelled cooking over the camp stove.

"I hope your day was more productive than mine," I said to Susan. Leanne was industriously stirring something that smelled as good as Chris could make.

Susan shrugged.

Over dinner, Leanne was quiet, thoughtful. I found out what she was thinking about when she plopped herself and her computer down next to me when I retreated to my tent for another round of data crunching.

"There are hummingbirds on the mainland too, but they're dragon's teeth," she said.

 

Susan and Leanne had collected a few hummingbird samples along with the rest, and Susan let me take charge of those samples "As long as you share anything especially interesting."

I ran the samples and then set up comparisons between the mainland hummingbirds and the island hummingbirds. I found that they were different species, but they shared some unexpected genes influencing both the beak area of the bird, and also influencing energy production.

I set up a few more queries to try to understand how the second set of genes might affect the birds, and then went to talk to Susan. She quickly agreed to let me come along the next day,

The next day, armed with nets and traps, I paddled a second canoe over to the mainland. The lake was still just after dawn, and the trip took longer than I expected. Long enough to make me think.

"Our hummingbirds shouldn't migrate, that instinct would kill them if they left behind the sorts of flowers that provide them with food," I said quietly after we'd drawn the canoes up on the sandy beach. "All migratory instincts should be dulled in anything that shows up on Mirabile... so the hummingbirds on the mainland should be a separate population from the hummingbirds on the island. It's far enough."

"So you think the matching genes are a coincidence?" Susan asked. She was right to sound skeptical.

"I'm not ready to commit to a hypothesis yet," I said, and got to work. The nets that we set up are called mist nets; they're so thin they're invisible. I monitored them all day so that I could take samples and tag the birds and then release them quickly, so they wouldn't be damaged by the nets. 

The traps were also designed not to harm the hummingbirds; they worked so well they didn't catch a single bird.

After lunch, I let Leanne show me the damaged trees. Like the trees on the island, these trees were tall and thin, but even at noon, their fronds dangled limply. A few were leaning precariously, but hadn't fallen yet.

"Do we know what usually makes the fronds move into their daytime position?" I asked.

"It's hydraulic," Leanne said. "Susan explained it to me, but all I really understood was that they're fluid inside the trunk, and the tree opens and closes vessels that contain the fluid... and there are structures that act like tiny pumps, all through the trunk of the tree..."

"Have you found out what's wrong?"

Leanne nodded. "Up at the top, some of the sap is leaking out," she said. "Like a spring of sap. It's messing up the whole system, and make the whole tree trunk less strong. Do you want to climb up and look?"

I declined, but I regretted that later on, back at our camp. "It says here that hummingbirds can eat tree sap that other sap-eating birds have started flowing, when nectar isn't available," I announced. We were gathered around the stove, because the evening had gotten surprisingly chilly for late summer. "I should have taken a closer look at that sap, to see if there were any signs."

"I have pictures," Susan said. I examined them on my computer, but I couldn't see any obvious signs that hummingbirds had been there, nor any reason to discount that hypothesis.

"Do you know what's causing the sap to leak? Some problem with the tree, or some animal or bird?"

Susan set her computer aside, signaling that it was a long story. "It's an interesting one," she said. "The tree has specific areas where the sap flows in fairly large streams, and it has defenses around that area -- really good defenses. I'm sure that no native Mirabilan creature could circumvent them to this degree, it's got to be something from earth, and something fairly new to the area. I'd almost suspect the hummingbirds -- they're dragon's teeth here -- but they're so small and delicate..."

"But they're dragon's teeth," I said. "Which means they might be capable of anything."

"Not anything," Susan said. "They have to obey the laws of physics..." But she looked as thoughtful as I felt.

I took another look at the genetics of the island hummingbird's beaks, and then set up a query to compare them to the beaks of known sap-eating birds. Call it a hunch, or call it curiosity -- and there's nothing better than curiosity in a jason, as Mama Jason says.

Then I squinted at images of hummingbird beaks until my eyes started showing me afterimages. I squeezed my eyes shut. "I wonder if hummingbirds are drinking that sap," I said. "Whether or not they're pecking apart the tree, if that sap is important to them, part of what helps them survive in the EC..."

"In the mainland EC," Susan said, as if I might have forgotten.

"There's got to be a connection," I said.

So the next day it was back to the mainland to catch more hummingbirds and analyze their stomach contents. The analysis showed yes, the hummingbirds were drinking sap from that tree, but then a few minutes later query about beaks came back with a negative. Beak design didn't match any known earth species, not exactly. But it was more highly reinforced than the usual hummingbird beak.

As I was mulling that over, Leanne slipped into the tent with her computer balanced across her arm and a confused expression on her face. "Ilanith? Will you check my simulation for me?"

"What's wrong?" I asked, reaching for the computer.

"It just doesn't make sense," Leanne said. "I don't think I did anything wrong, but..."

But her analysis was showing that one of the flowers the hummingbirds were supposed to be living off of -- one of the flowers in the island's carefully designed ecosystem -- had mutated so that its nectar was no longer accessible to hummingbirds. A slightly deeper flower, and a Mirabilan insect to crawl down inside, while the hummingbird was thwarted.

The simulation analyzing the effects of this change showed the hummingbird population dying in the spring, when this flower was the only one that bloomed early enough. They needed constant sustenance, so they needed that flower...

"But they couldn't have lived off of this flower..."

"It's not growing at all on the mainland, that's why I checked it on the island," Leanne said.

"Yes, there's something here. Your simulation is fine, but I'm not sure what it means. Except that we'd probably better check to see if hummingbirds on the island are living off sap, somehow, without killing the trees?"

So it was another round of data gathering, and then another night sitting around the camp stove. Susan was running simulations, and frowning at the results. "If it's the hummingbirds," she announced. "And I'm starting to think it is them, pecking the trees apart for food with their dragon's teeth beaks -- they've got enough food to keep them going indefinitely. They'll just keep breeding more hummingbirds until they've run out of trees, and then they'll either adapt again somehow or die. But until then, they're just too successful."

I was frowning too, at the confirmation that island hummingbirds were drinking sap.

"But my hummingbirds have the same beak, and they're..." I shrugged. 

Susan laughed. "It's funny how mine are too successful, and yours are not successful enough."

"If only we could average them out," I said.

Then I paused, thinking about what I'd just said. 

"What?" Susan said.

"I'll tell you later," I said, turning to my computer and starting to type. Susan leaned over my shoulder.

About half way through setting up my query, Susan got it. 

When I finished, she was still setting up her own query, and her own simulations.

We settled back, jittery and impatient, to wait for our results to come in.

Finally, a computer pinged -- it was mine, not that either of us were keeping track -- and we looked at the evidence together. My hummingbirds were not the same species as the dragon's teeth on the mainland, but they shared some vital genes.

"It's not dragon's teeth, it's hybrids," I said. "The island hummingbirds are hybrids."

"Let's go tell Mama Jason," Susan said.

 

By the time we'd dragged Mama Jason away from the conference, Leanne and Noisy had both got wind of our excitement and were hovering like hummingbirds expecting a flower to open.

Luckily, none of the conference delegates tagged along as well. I didn't want to publicize our findings until I'd gotten Mama Jason's reaction -- just in case Susan and I had overlooked something.

We settled down by the stove; Mama Jason claimed the comfortable chair, and Noisy sat in the other chair, but Susan and I didn't mind sitting on the ground. I propped my computer up on a camp stool so that everyone could see the data.

"We don't usually worry about hybrids," I explained. "On Mirabile, dragon's teeth are the dominant process for the formation of new species, but Susan and Jen and I read about hybrids in ships' records a long time ago, and they stuck with me because they're a little like an earth-authentic version of dragon's teeth. Though they're much less ... unpredictable."

Mama Jason snorted. Unpredictable was an understatement when it came to dragon's teeth, I'd give her that.

"Less dangerous, too," I admitted. "They don't suddenly pop up with totally new traits and behavior out of a population that you thought you understood. But they're a way that new traits could work its way into a population, even back on earth where genes tended to stay within a species."

"On earth, they thought that many earth-authentic species -- like all of the big cats -- shared traits via hybridization. It helped them to survive when their EC changed; it allowed useful genes from close relatives to spread."

"Are you trying to tell me that--"

"I'm trying to tell you that hummingbirds shouldn't survive in this EC at all. One of the plants they depend on died out on the mainland, and mutated on the island. It wasn't obvious, that's why we didn't catch it right away, but the dragon's teeth on the mainland were dragon's teeth because they needed to be -- because only they could survive, and only by feeding on sap from a Mirabilan tree -- with devastating results for the tree."

"But the hummingbirds on the island were stabilized." That was Noisy, right to the point.

"Which is why we didn't get dragon's teeth, we got hybrids _from_ the dragon's teeth. Say just one mainland hummingbird made it over to the island. If its children were able to eat the sap, they'd be able to survive -- at a cost. Our hummingbirds are sick, and it's directly because they're hybrids. Hybrids aren't always successful, and these hybrids have some problems at the cellular level -- their energy production system has mismatching genes, and it's less efficient than it should be. That's also why they haven't killed any trees on the island yet...they're not healthy, and it keeps them from being as destructive as their parent species on the mainland."

"Let me take a look at that," Mama Jason said, reaching out for the computer. She didn't doubt me, she just wanted to see for herself.

"So does that mean we're going to have to grit our teeth and approve pollination by hand?" Noisy asked.

"I don't know," I said. "I just figured out the problem. Solutions might take a bit longer."

"Fair enough," Noisy said.

"We're not going to pollinate by hand," Mama Jason growled. "We're going to figure out something, so I want all of you to think it over and we'll meet again tomorrow. Meanwhile, I'm putting the conference on hold."

Noisy grinned. "Finally, an excuse to stop going to that conference and do something productive," he said.

"You'd better believe it," Mama Jason said.

 

I woke up in the middle of the night, my mind racing. Leanne was asleep, but when I slipped out of the tent, Susan was sitting in the comfortable chair already.

"I have an idea," we both whispered the instant we set eyes on each other. Then we laughed.

We dragged our chairs a bit further away from my tent so that we wouldn't wake Leanne, and then looked at each other expectantly.

"You first," I told Susan. 

She pulled out her computer and showed me an article from ships' records about a form of genetic selection that allowed an egg to choose compatible sperm. "We can splice some genes like this into a batch of island hummingbirds, and make it a better bet that even the hybrids will turn up a healthy cellular metabolism. It might cost us the Mirabilan trees, but the island is too important to leave to chance."

"That's better than splicing up each generation by hand," I said, admiring Susan's research skills. "And much better than pollinating by hand."

"What about you?"

So I got out my computer and showed her a diagram I'd mocked up of the tiny biological pumps within the Mirabilan trees. Then I drew a simple design for a little metal gadget that could be drilled into the tree, hooking onto the biological pumps and diverting a small amount of sap into a small reservoir that only hummingbirds with their long, hybridly strong beaks would be able to access.

"It's just an idea," I said. "I thought I'd show it to Noisy in the morning." He'd been a bellmaker before he became a jason; he knew something about making things.

Susan laughed. "You know, I'd been thinking about how to modify the genes of that tree so that it would grow flowers or something--"

"We're not quite there yet," I said. "Not with Mirabilan flora."

"Someday I bet that'll be part of the jason's toolkit," Susan said. "But until then..."

 

Mama Jason liked it. She managed to get the conference attendees to agree to our proposal without forcing us to stand in front of them, for which I was grateful. And Noisy arranged to have the sap diversion devices produced.

It took a few months to design and test them, and by then it was winter. But in the spring, we all -- me, Susan, Mama Jason, Noisy, and Leanne -- returned to the island with enough little devices to cover all the Mirabilan trees in hummingbird fountains. 

"We'll have to check on the trees occasionally, to make sure the fountains don't get dislodged... But Cure Island should once again be a self-sustaining ecosystem," I said.

"The new hummingbirds that we hatched this year are looking good and healthy," Mama Jason confirmed. "We've let them fly free, though we've been feeding them an artificial solution to supplement their diet."

"I wonder whether the earth scientists that set up our dragon's tooth system ever spared one second to think about hybrids," Susan said.

I hadn't spared one second to wonder, but now that the subject had been broached, I had a few questions too. "They have a lot of protections around dragon's teeth, to make them more likely to produce something viable. Did we turn those protections off, when we stabilized the population here by turning off their ability to produce dragon's teeth?"

"We may never know," Noisy said.

"Don't say that!" Leanne protested. "It might be in ships' records somewhere, and if it is, I'm going to find it."

She'd recently been apprenticed to Alison, one of the new jasons who specialized in records, so her words had some force to them.

Mama Jason nodded. "If you do, you'll be following in the tradition of jasons who make important discoveries," she said, her eyes on Susan and me.

We grinned at her, and then we all started drilling. Soon, the trees were spotted with attractive additions -- bright red, sturdy metallic flowers.

And as I watched, a hummingbird flew over and stuck its beak into one of them.

**Author's Note:**

> Some Sources:
> 
> https://www.quantamagazine.org/interspecies-hybrids-play-a-vital-role-in-evolution-20170824/  
> https://www.quantamagazine.org/genetic-struggles-within-cells-may-create-new-species-20170927/  
> https://www.quantamagazine.org/choosy-eggs-may-pick-sperm-for-their-genes-defying-mendels-law-20171115/


End file.
